Back to top

Image: Shutterstock

Merck's Keytruda Meets PFS Endpoint in Breast Cancer Study

Read MoreHide Full Article

Merck & Co., Inc. (MRK - Free Report) announced that the pivotal phase III breast cancer study, KEYNOTE-355 evaluating PD-1 inhibitor, Keytruda, has met one of its dual primary endpoints of progression-free survival (“PFS”). The study is evaluating the blockbuster drug in combination with chemotherapy as a first line treatment for patients with metastatic triple-negative breast cancer (mTNBC) whose tumors expressed PD-L1 [combined positive score (“CPS”) ≥10].

An interim analysis of the KEYNOTE-355 study done by an independent Data Monitoring Committee demonstrated that the Keytruda combination regimen achieved a statistically significant and clinically meaningful improvement in PFS versus chemotherapy alone. Moreover, the committee also recommended continuation of the study without any changes for the evaluation of second primary endpoint of overall survival (“OS”).

The two-part KEYNOTE-355 study evaluated a combination of Keytruda and one of three different chemotherapies — nab-paclitaxel, paclitaxel or gemcitabine/carboplatin — versus placebo plus one of the three chemotherapy regimens in mTNBC patients who have not received any prior treatment with chemotherapy in the metastatic setting. The study included patient population who have CPS ≥ 1 and CPS ≥10. Detailed data from the interim analysis will be presented at an upcoming medical congress and will also be discussed with the FDA.

Merck is also evaluating Keytruda in two other registration-enabling studies — KEYNOTE-242 and KEYNOTE-522 — as a treatment option for mTNBC patients. Previously announced data from the KEYNOTE-522 study has shown that the drug in combination with chemotherapy achieved positive results as neoadjuvant therapy in mTNBC patients. Merck’s breast cancer clinical development program for Keytruda includes multiple internal and external collaborative studies. Please note that Keytruda is not approved for any breast cancer indication.

We note that Roche received approval for its PD-L1 inhibitor, Tecentriq, in combination with Bristol-Myers’ (BMY - Free Report) Abraxane last year for the treatment of adult patients with unresectable, locally advanced or mTNBC.

Per the press release, approximately 15-20% of breast cancer patients are diagnosed with mTNBC, which is also a difficult-to-treat breast cancer indication. Successful development in first-line and neoadjuvant setting will boost the sales of this already in demand drug.

Merck’s stock has gained 5.4% in the past year compared with the industry’s growth of 12.5%. The underperformance can be partly attributed to lower-than-expected fourth-quarter results.


Sales of Keytruda added almost $11.1 billion in 2019, growing 55% year over year. The drug generated nearly a quarter of Merck’s total revenues. Keytruda is now already approved for use in several oncology indications across different tumor types in the United States. Meanwhile, the company has the industry’s largest immuno-oncology clinical research program including more than 1,000 clinical studies evaluating Keytruda in multiple cancer indications in different treatment settings.

However, competition in the immuno-oncology market is rising with the availability of several other drugs including Pfizer’s (PFE - Free Report) Bavencio and AstraZeneca’s (AZN - Free Report) Imfinzi.

Zacks Rank

Merck currently carries a Zacks Rank #3 (Hold). You can see the complete list of today’s Zacks #1 Rank (Strong Buy) stocks here.

5 Stocks Set to Double

Each was hand-picked by a Zacks expert as the #1 favorite stock to gain +100% or more in 2020. Each comes from a different sector and has unique qualities and catalysts that could fuel exceptional growth.

Most of the stocks in this report are flying under Wall Street radar, which provides a great opportunity to get in on the ground floor.

Today, See These 5 Potential Home Runs >>

Published in